31.Either you or on of your students________to attend the meeting that is due tomorrow.
--The news is spreading from mouth to mouth. --Yes, it has become__________ talk of__________ town.
Why haven't you finished your homework yet? You___________ to have finished it by last Sunday.
. Could you give me a hand __________from the car, please?
--I'm told that John had another car accident this morning. --I believe not. He _________so careless.
The Bunsen Burner is so named because it is thought ___________ by Robert Bunsen.